Influence of changes in physical activity on frequency of hospitalization in chronic obstructive pulmonary disease

BACKGROUND AND OBJECTIVE: To evaluate whether changes in regular physical activity (PA) in patients with chronic obstructive pulmonary disease (COPD) affect the rate of hospitalizations for COPD exacerbation (eCOPD). METHODS: Five hundred forty-three ambulatory clinic patients being treated for COPD were prospectively identified. PA was self-reported by patients, and the level was established by the distance they walked (km/day) at least 3 days per week. Hospitalizations were recorded from hospital databases. All patients with at least a 2-year follow-up after enrollment were included in the analysis. The response variable was the number of hospitalizations for eCOPD within the 3-year period from 2 to 5 years after study enrollment. RESULTS: Three hundred ninety-one survivors were studied. Mean forced expiratory volume in 1 s was 52% (±14%) of the predicted value. Patients who maintained a lower level of PA had an increased rate of hospitalization (odds ratio 1.901; 95% confidence interval 1.090-3.317). After having had the highest level of PA, those patients who decreased their PA in the follow-up showed an increasing rate of hospitalizations (odds ratio 2.134; 95% confidence interval 1.146-3.977). CONCLUSIONS: Patients with COPD with a low level of PA or who reduced their PA over time were more likely to experience a significant increase in the rate of hospitalization for eCOPD. Changes to a higher level of PA or maintaining a moderate or high level of PA over time, with a low intensity activity such as walking for at least 3-6 km/day, could reduce the rate of hospitalizations for eCOPD.